.\"
.\" avrdude - A Downloader/Uploader for AVR device programmers
.\" Copyright (C) 2001, 2002, 2003, 2005 - 2023 Hans Eirik Bull,
.\" Stefan Rueger and Joerg Wunsch
.\"
.\" This program is free software; you can redistribute it and/or modify
.\" it under the terms of the GNU General Public License as published by
.\" the Free Software Foundation; either version 2 of the License, or
.\" (at your option) any later version.
.\"
.\" This program is distributed in the hope that it will be useful,
.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
.\" GNU General Public License for more details.
.\"
.\" You should have received a copy of the GNU General Public License
.\" along with this program. If not, see <http://www.gnu.org/licenses/>.
.\"
.\"
.Dd January 15, 2023
.Os
.Dt AVRDUDE 1
.Sh NAME
.Nm avrdude
.Nd driver program for ``simple'' Atmel AVR MCU programmer
.Sh SYNOPSIS
.Nm
.Op Fl p, \-part Ar partname
.Op Fl b, \-baud Ar baudrate
.Op Fl B, \-bitclock Ar bitclock
.Op Fl c, \-programmer Ar programmer-id
.Op Fl C, \-config Ar config-file
.Op Fl N, \-noconfig
.Op Fl A
.Op Fl D, \-noerase
.Op Fl e, \-erase
.Oo Fl E Ar exitspec Ns
.Op \&, Ns Ar exitspec
.Oc
.Op Fl F
.Op Fl i Ar delay
.Op Fl l, \-logfile Ar logfile
.Op Fl n, \-test-memory
.Op Fl O, \-osccal
.Op Fl P, \-port Ar port
.Op Fl r, \-reconnect
.Op Fl q, \-quell
.Op Fl T Ar cmd
.Op Fl t, \-terminal
.Op Fl U, \-memory Ar memory:op:filename:filefmt
.Op Fl v, \-verbose
.Op Fl x Ar extended_param
.Op Fl V, \-noverify-memory
.Op Fl \-version
.Sh DESCRIPTION
.Nm Avrdude
is a program for downloading and uploading on-chip memories of Atmel AVR
microcontrollers.
.Nm Avrdude
supports Atmel's STK500 programmer,
Atmel's AVRISP and AVRISP mkII devices,
Atmel's STK600,
Atmel's JTAG ICE (mkI, mkII and 3, the latter two also in ISP mode),
programmers complying to AppNote AVR910 and AVR109 (including the Butterfly),
as well as a simple hard-wired
programmer connected directly to a
.Xr ppi 4
or
.Xr parport 4
parallel port, or to a standard serial port.
In the simplest case, the hardware consists just of a
cable connecting the respective AVR signal lines to the parallel port.
.Pp
The MCU is programmed in
.Em serial programming mode ,
so, for the
.Xr ppi 4
based programmer, the MCU signals
.Ql /RESET ,
.Ql SCK ,
.Ql SDI
and
.Ql SDO
of the AVR's SPI interface need to be connected to the
parallel port; older boards might use the labels MOSI for SDO or MISO for SDI.
Optionally, some otherwise
unused output pins of the parallel port can be used to supply power
for the MCU part, so it is also possible to construct a passive
stand-alone programming device.  Some status LEDs indicating the
current operating state of the programmer can be connected, and a
signal is available to control a buffer/driver IC 74LS367 (or
74HCT367).  The latter can be useful to decouple the parallel port
from the MCU when in-system programming is used.
.Pp
A number of equally simple bit-bang programming adapters that connect
to a serial port are supported as well, among them the popular
Ponyprog serial adapter, and the DASA and DASA3 adapters that used to
be supported by uisp(1).
Note that these adapters are meant to be attached to a physical serial
port.
Connecting to a serial port emulated on top of USB is likely to not
work at all, or to work abysmally slow.
.Pp
If you happen to have a Linux system with at least 4 hardware GPIOs
available (like almost all embedded Linux boards) you can do without
any additional hardware - just connect them to the SDO, SDI, RESET
and SCK pins on the AVR and use the linuxgpio programmer type. It bitbangs
the lines using the Linux sysfs GPIO interface. Of course, care should
be taken about voltage level compatibility. Also, although not strictly
required, it is strongly advisable to protect the GPIO pins from
overcurrent situations in some way. The simplest would be to just put
some resistors in series or better yet use a 3-state buffer driver like
the 74HC244. Have a look at https://kolev.info/blog/2013/01/06/avrdude-linuxgpio/ for a more
detailed tutorial about using this programmer type.
.Pp
Under a Linux installation with direct access to the SPI bus and GPIO
pins, such as would be found on a Raspberry Pi, the ``linuxspi''
programmer type can be used to directly connect to and program a chip
using the built in interfaces on the computer. The requirements to use
this type are that an SPI interface is exposed along with one GPIO
pin. The GPIO serves as the reset output since the Linux SPI drivers
do not hold chip select down when a transfer is not occurring and thus
it cannot be used as the reset pin. A readily available level
translator should be used between the SPI bus/reset GPIO and the chip
to avoid potentially damaging the computer's SPI controller in the
event that the chip is running at 5V and the SPI runs at 3.3V. The
GPIO chosen for reset can be configured in the avrdude configuration
file using the
.Li reset
entry under the linuxspi programmer, or
directly in the port specification. An external pull-up resistor
should be connected between the AVR's reset pin and Vcc. If Vcc is not
the same as the SPI voltage, this should be done on the AVR side of
the level translator to protect the hardware from damage.
.Pp
The
.Fl P Ar portname
option for this programmer defaults to
.Li /dev/spidev0.0:/dev/gpiochip0 .
.Pp
Atmel's STK500 programmer is also supported and connects to a serial
port.
Both, firmware versions 1.x and 2.x can be handled, but require a
different programmer type specification (by now).
Using firmware version 2, high-voltage programming is also supported,
both parallel and serial
(programmer types stk500pp and stk500hvsp).
.Pp
Wiring boards (e.g. Arduino Mega 2560 Rev3) are supported, utilizing STK500
V2.x protocol, but a simple DTR/RTS toggle is used to set the boards into
programming mode.  The programmer type is ``wiring''.  Note that the -D option
will likely be required in this case, because the bootloader will rewrite the
program memory, but no true chip erase can be performed.
.Pp
Serial bootloaders that run a skeleton of the STK500 1.x protocol are
supported via their own programmer type ``arduino''.  This programmer works
for the Arduino Uno Rev3 or any AVR that runs the Optiboot bootloader.
.Pp
Urprotocol is a leaner version of the STK500 1.x protocol that is designed
to be backwards compatible with STK500 v1.x, and allows bootloaders to be
much smaller, e.g., as implemented in the urboot project
https://github.com/stefanrueger/urboot. The programmer type ``urclock''
caters for these urboot programmers. Owing to its backward compatibility,
bootloaders that can be served by the arduino programmer can normally
also be served by the urclock programmer. This may require specifying the
size of (to avrdude) unknown bootloaders in bytes using the
.Fl x Ar bootsize=<n>
option, which is necessary for the urclock programmer to enable it to
protect the bootloader from being overwritten. If an unknown bootloader
has EEPROM read/write capability then the option -x eepromrw informs
avrdude -c urclock of that capability.
.Pp
The BusPirate is a versatile tool that can also be used as an AVR programmer.
A single BusPirate can be connected to up to 3 independent AVRs. See
the section on
.Em extended parameters
below for details.
.Pp
Atmel's STK600 programmer is supported in ISP and high-voltage
programming modes, and connects through the USB.
For ATxmega devices, the STK600 is supported in PDI mode.
For ATtiny4/5/9/10 devices, the STK600 and AVRISP mkII are supported in TPI mode.
.Pp
The simple serial programmer described in Atmel's application note
AVR910, and the bootloader described in Atmel's application note
AVR109 (which is also used by the AVR Butterfly evaluation board), are
supported on a serial port.
.Pp
Atmel's JTAG ICE (mkI, mkII, and 3) is supported as well to uploading and
download memory areas of an AVR target (no support for on-chip debugging).
For the JTAG ICE mkII, JTAG, debugWIRE and ISP mode are supported,
provided it has a firmware revision of at least 4.14 (decimal). JTAGICE3
also supports all of JTAG, debugWIRE, and ISP mode. See below for the
limitations of debugWIRE. For ATxmega devices, the JTAG ICE mkII is
supported in PDI mode, provided it has a revision 1 hardware and firmware
version of at least 5.37 (decimal). For ATxmega devices, the JTAGICE3 is
supported in PDI mode.
.Pp
Atmel-ICE (ARM/AVR) is supported in all modes (JTAG, PDI for Xmega, debugWIRE,
ISP, UPDI).
.Pp
Atmel's XplainedPro boards, using the EDBG protocol (CMSIS-DAP compatible),
are supported using the "jtag3" programmer type.
.Pp
Atmel's XplainedMini boards, using the mEDBG protocol,
are also supported using the "jtag3" programmer type.
.Pp
The AVR Dragon is supported in all modes (ISP, JTAG, HVSP, PP, debugWIRE).
When used in JTAG and debugWIRE mode, the AVR Dragon behaves similar to a
JTAG ICE mkII, so all device-specific comments for that device
will apply as well.
When used in ISP mode, the AVR Dragon behaves similar to an
AVRISP mkII (or JTAG ICE mkII in ISP mode), so all device-specific
comments will apply there.
In particular, the Dragon starts out with a rather fast ISP clock
frequency, so the
.Fl B Ar bitclock
option might be required to achieve a stable ISP communication.
For ATxmega devices, the AVR Dragon is supported in PDI mode, provided it
has a firmware version of at least 6.11 (decimal).
.Pp
The USBasp ISP, USBtinyISP, avrftdi and CH341A adapters are also supported,
provided
.Nm avrdude
has been compiled with libusb support. USBasp ISP and USBtinyISP both
feature simple firmware-only USB implementations, running on an ATmega8
(or ATmega88), or ATtiny2313, respectively. CH341A programmers connect
directly to the AVR target. Their SPI bit clock is approximately 1.7 MHz
and cannot be changed. As a consequence, the AVR target must have a CPU
frequency of 6.8 MHz or more: factory-set AVR parts, which typically run
on an internal oscillator between 1 MHz and 1.6 MHz, cannot be programmed
using -c ch341a. If libftdi has  has been compiled in
.Nm avrdude ,
the avrftdi device adds support for many programmers using FTDI's 2232C/D/H
and 4232H parts running in MPSSE mode, which hard-codes (in the chip)
SCK to bit 1, SDO to bit 2, and SDI to bit 3. Reset is usually bit 4.
.Pp
The Atmel DFU bootloader is supported in both, FLIP protocol version 1
(AT90USB* and ATmega*U* devices), as well as version 2 (Xmega devices).
See below for some hints about FLIP version 1 protocol behaviour.
.Pp
The MPLAB(R) PICkit 4/5 and MPLAB(R) SNAP, are supported in JTAG, TPI, ISP,
PDI and UPDI mode.
The Curiosity Nano board is supported in UPDI mode. It is dubbed
.Dq PICkit on Board ,
thus the name
.Pa pkobn_updi .
.Pp
SerialUPDI programmer implementation is based on Microchip's
.Em pymcuprog Li https://github.com/microchip-pic-avr-tools/pymcuprog
utility, but it also contains some performance improvements included in
Spence Konde's
.Em DxCore
Arduino core
.Li https://github.com/SpenceKonde/DxCore .
In a nutshell, this programmer consists of simple USB->UART adapter, diode
and couple of resistors. It uses serial connection to provide UPDI interface.
See the texinfo documentation for more details and known issues.
.Pp
The jtag2updi programmer is supported, and can program AVRs with a UPDI
interface. Jtag2updi is just a firmware that can be loaded onto an AVR,
which enables it to interface with avrdude using the jtagice mkii protocol
via a serial link.
.Li https://github.com/ElTangas/jtag2updi
.Pp
The Micronucleus bootloader is supported for both protocol version V1
and V2. As the bootloader does not support reading from flash memory,
use the
.Fl V
option to prevent AVRDUDE from verifying the flash memory.
See the section on
.Em extended parameters
for Micronucleus specific options.
.Pp
The Teensy bootloader is supported for all AVR boards.
As the bootloader does not support reading from flash memory,
use the
.Fl V
option to prevent AVRDUDE from verifying the flash memory.
See the section on
.Em extended parameters
for Teensy specific options.
.Pp
Input files can be provided, and output files can be written in
different file formats, such as raw binary files containing the data
to write to the chip, Intel Hex format, or Motorola S-Record
format.  There are a number of tools available to produce those files,
like
.Xr asl 1
as a standalone assembler, or
.Xr avr-objcopy 1
for the final stage of the GNU toolchain for the AVR microcontroller.
.Pp
Provided
.Xr libelf 3
was present when compiling
.Nm avrdude ,
the input file can also be the final ELF file as produced by the linker.
The appropriate ELF section(s) will be examined, according to the memory
area to write to.
.Pp
.Nm Avrdude
can program the EEPROM and flash ROM memory cells of supported AVR
parts.  Where supported by the serial instruction set, fuse bits and
lock bits can be programmed as well.  These are implemented within
.Nm
as separate memory types and can be programmed using data from a file
(see the
.Fl U
option) or from terminal mode (see the
.Ar dump
and
.Ar write
commands).  It is also possible to read the chip (provided it has not
been code-protected previously, of course) and store the data in a
file.  Finally, a ``terminal'' mode is available that allows one to
interactively communicate with the MCU, and to display or program
individual memory cells.
On some programmers some settings of the programmer itself can be examined and
changed from within terminal mode as well; see the
.Em Terminal mode
section.
.Ss Options
In order to control all the different operation modi, a number of options
need to be specified to
.Nm avrdude .
.Bl -tag -offset indent -width indent
.It Fl p \-part Ar partname
This option specifies the MCU connected to the programmer. The MCU
descriptions are read from the config file. To see a list of currently
supported MCUs use ? as partname, which will print the part ids and
official part names. Depending on the used shell, ? may need to be quoted
as in "?" or \\?. In connection with -v, this will also print a list of
variant part names followed by an optional colon, the package code and
some absolute maximum ratings. The part id, their official part name, any
of the full variant part names or their initial part up to a dash can be
used to specify a part with the -p option. If -p ? is specified with a
specific programmer, see -c below, then only those parts are output that
the programmer expects to be able to handle, together with the programming
interface(s) that can be used in that combination. In reality there can be
deviations from this list, particularly if programming is directly via a
bootloader.
.Pp
The following parts need special attention:
.Bl -tag -width "ATmega1234"
.It "AT90S1200"
The ISP programming protocol of the AT90S1200 differs in subtle ways
from that of other AVRs.  Thus, not all programmers support this
device.  Known to work are all direct bitbang programmers, and all
programmers talking the STK500v2 protocol.
.It "AT90S2343"
The AT90S2323 and ATtiny22 use the same algorithm.
.It "ATmega2560, ATmega2561"
Flash addressing above 128 KB may not be supported by all
programming hardware.
.It "ATtiny11"
The ATtiny11 can only be
programmed in high-voltage serial mode.
.El
.It Fl p \-part Ar wildcard/flags
Run developer options for MCUs that are matched by wildcard. Whilst
their main use is for developers some flags can be of utility for users, e.g.,
avrdude -p m328p/S outputs AVRDUDE's understanding of ATmega328P MCU properties;
for more information run avrdude -p x/h.
.It Fl b \-baud Ar baudrate
Override the RS-232 connection baud rate specified in the respective
programmer's entry of the configuration file or defined by the default_baudrate
entry in your user configuration file
.Pa ${HOME}/.config/avrdude/avrdude.rc
or
.Pa ${HOME}/.avrduderc
if no baudrate was defined for this programmer.
.It Fl r \-reconnect
Opens the serial port at 1200 baud and immediately closes it, waits 400 ms
for each -r on the command line and then establishes communication with
the programmer. This is commonly known as a "1200bps touch", and is used
to trigger programming mode for certain boards like Arduino Leonardo,
Arduino Micro/Pro Micro and the Arduino Nano Every. Longer waits, and
therefore multiple -r options, are sometimes needed for slower, less
powerful hosts.
.It Fl B \-bitclock Ar bitclock
Specify the bit clock period for the JTAG, PDI, TPI, UPDI, or ISP
interface. The value is a floating-point number in microseconds.
Alternatively, the value might be suffixed with "Hz", "kHz" or
"MHz" in order to specify the bit clock frequency rather than a
period. Some programmers default their bit clock value to a 1
microsecond bit clock period, suitable for target MCUs running at 4
MHz clock and above. Slower MCUs need a correspondingly higher bit
clock period. Some programmers reset their bit clock value to the
default value when the programming software signs off, whilst others
store the last used bit clock value. It is recommended to always
specify the bit clock if read/write speed is important.
You can use the 'default_bitclock' keyword in your
.Pa ${HOME}/.config/avrdude/avrdude.rc
or
.Pa ${HOME}/.avrduderc
file to assign a default value to keep from having to specify this
option on every invocation.
.Pp
Note that some official Microchip programmers store the bitclock setting and
will continue to use it until a different value is provided. This applies to
"2nd gen" programmers (AVRISPmkII, AVR Dragon, JTAG ICE mkII, STK600) and
"3rd gen"programmers (JTAGICE3, Atmel ICE, Power Debugger). "4th gen"
programmers (PICkit 4, MPLAB SNAP) will store the last user-specified bitclock
until the programmer is disconnected from the computer.
.It Fl c \-programmer Ar programmer-id
Use the programmer specified by the argument.  Programmers and their pin
configurations are read from the config file (see the
.Fl C
option).  New pin configurations can be easily added or modified
through the use of a config file to make
.Nm avrdude
work with different programmers as long as the programmer supports the
Atmel AVR serial program method.  You can use the 'default_programmer'
keyword in your
.Pa ${HOME}/.config/avrdude/avrdude.rc
or
.Pa ${HOME}/.avrduderc
file to assign a default programmer to keep from having to specify this
option on every invocation. A full list of all supported programmers is
output to the terminal by using ? as programmer-id. Depending on the used
shell, ? may need to be quoted as in "?" or \\?. If -c ? is specified with
a specific part, see -p above, then only those programmers are output that
expect to be able to handle this part, together with the programming
interface(s) that can be used in that combination. In reality there can be
deviations from this list, particularly if programming is directly via a
bootloader.
.It Fl c \-programmer Ar wildcard/flags
Run developer options for programmers that are matched by wildcard. Whilst
their main use is for developers some flags can be of utility for users, e.g.,
avrdude -c usbtiny/S shows AVRDUDE's understanding of usbtiny's properties;
for more information run avrdude -c x/h.
.It Fl C \-config Ar config-file
Use the specified config file to load configuration data.  This file
contains all programmer and part definitions that
.Nm avrdude
knows about.
See the config file, located at
.Pa ${PREFIX}/etc/avrdude.conf ,
which contains a description of the format.
.Pp
If
.Ar config-file
is written as
.Pa +filename
then this file is read after the system wide and user configuration
files. This can be used to add entries to the configuration
without patching your system wide configuration file. It can be used
several times, the files are read in same order as given on the command
line.
.It Fl N \-noconfig
Do not load the personal configuration file that is usually located at
~/.config/avrdude/avrdude.rc, ~/.avrduderc or in the same directory as the
avrdude executable
.It Fl A
Disable the automatic removal of trailing-0xFF sequences in file
input that is to be programmed to flash and in AVR reads from
flash memory. Normally, trailing 0xFFs can be discarded, as flash
programming requires the memory be erased to 0xFF beforehand.
.Fl A
should be used when the programmer hardware, or bootloader
software for that matter, does not carry out chip erase and
instead handles the memory erase on a page level. Popular
Arduino bootloaders exhibit this behaviour; for this reason
.Fl A
is engaged by default when specifying
. Fl c
arduino.
.It Fl D \-noerase
Disable auto-erase for flash. When the
.Fl U \-memory
option for writing to any flash memory is specified,
.Nm
will perform a chip erase before starting any of the programming
operations, since it generally is a mistake to program the flash without
performing an erase first.  This option disables that. Auto-erase is not
used for ATxmega parts nor for the UPDI (AVR8X family) parts as these can
use page erase before writing each page so no explicit chip erase is
required. Note, however, that any flash page not affected by the current
operation will retain its previous contents. Setting
.Fl D
implies
.Fl A.
.It Fl e \-erase
Causes a chip erase to be executed. This will reset the contents of the
flash ROM and EEPROM to the value
.Ql 0xff ,
and clear all lock bits.
Except for ATxmega and UPDI (AVR8X family) devices, all of which can use
page erase, it is basically a prerequisite command before the flash ROM
can be reprogrammed again.  The only exception would be if the new
contents would exclusively cause bits to be programmed from the value
.Ql 1
to
.Ql 0 .
This option carries out the chip erase at the beginning, before any of the
.Fl U,
.Fl T
or
.Fl t
options are processed. If a chip erase is required in at a certain
position within the sequence of
.Fl U,
.Fl T
or
.Fl t
options it is recommended to use -T erase instead which is processed in
the given command line order.
.Pp
In absence of an explicit
.Fl e
or
.Fl D
option
.Nm
tries to augur from the command line whether or not the chip should be
auto-erased at the beginning. If
.Nm
detects a
.Fl U
command that writes to flash then auto-erase will be carried out before
any other programming unless a -T erase commad has been detected
beforehand and unless flash is read before writing to it. For the purpose
of this analysis any terminal command is considered to possibly read
flash.
.Pp
Note that for reprogramming EEPROM cells, no explicit prior chip
erase is required since the MCU provides an auto-erase cycle in that
case before programming the cell.
.It Xo Fl E Ar exitspec Ns
.Op \&, Ns Ar exitspec
.Xc
Pass
.Ar exitspec
to the chosen programmer. The interpretation of the exitspec parameter
depends on the programmer itself. See below for a list of programmers
accepting exitspec parameter options or issue
.Nm
-E help ... to see the options of the chosen programmer.
.It Fl F
Normally,
.Nm
tries to verify that the device signature read from the part is
reasonable before continuing.  Since it can happen from time to time
that a device has a broken (erased or overwritten) device signature
but is otherwise operating normally, this option is provided to
override the check.
Also, for programmers like the Atmel STK500 and STK600 which can
adjust parameters local to the programming tool (independent of an
actual connection to a target controller), this option can be used
together with
.Fl t
to continue in terminal mode.
Moreover, the option allows to continue despite failed initialization
of connection between a programmer and a target.
.It Fl i Ar delay
For bitbang-type programmers, delay for approximately
.Ar delay
microseconds between each bit state change.
If the host system is very fast, or the target runs off a slow clock
(like a 32 kHz crystal, or the 128 kHz internal RC oscillator), this
can become necessary to satisfy the requirement that the ISP clock
frequency must not be higher than 1/4 of the CPU clock frequency.
This is implemented as a spin-loop delay to allow even for very
short delays.
On Unix-style operating systems, the spin loop is initially calibrated
against a system timer, so the number of microseconds might be rather
realistic, assuming a constant system load while
.Nm
is running.
On Win32 operating systems, a preconfigured number of cycles per
microsecond is assumed that might be off a bit for very fast or very
slow machines.
.It Fl l \-logfile Ar logfile
Use
.Ar logfile
rather than
.Va stderr
for diagnostics output.
Note that initial diagnostic messages (during option parsing) are still
written to
.Va stderr
anyway.
.It Fl n \-test-memory
No-write: disables writing data to the MCU whilst processing -U
(useful for debugging
.Nm avrdude
). The terminal mode continues to write to the device.
.It Fl O \-osccal
Perform an RC oscillator run-time calibration according to Atmel
application note AVR053.
This is only supported on the STK500v2, AVRISP mkII, and JTAG ICE mkII
hardware.
Note that the result will be stored in the EEPROM cell at address 0.
.It Fl P \-port Ar port
Use
.Ar port
to identify the connection through which the programmer is attached. This
can be a parallel, serial, spi or linuxgpio connection. The programmer
normally specifies the connection type; in absence of a -P specification,
system-dependent default values
.Pa default_parallel ,
.Pa default_serial ,
.Pa default_spi ,
or
.Pa default_linuxgpio
from the configuration file are used. If you need to use a different port,
use this option to specify the alternate port name.
.Pp
USB-only programmers normally do not need the port option be specified as
they are automatically identified via their vendor and product IDs from
avrdude.conf or .avrduderc. Only when there are multiple programmers of
the same type plugged into the host computer is the -P option needed, see
below. Some -c programmers, however, ignore the -P option altogether, eg,
teensy, ch341a or avrftdi; these cannot distinguish multiple plugged-in
programmers.
.Pp
If
.Nm
has been configured with libserialport support, a serial port can be specified
using a predefined serial adapter type in avrdude.conf or .avrduderc, e.g.,
.Ar ch340
or
.Ar ft232r .
If more than one serial adapter of the same type is connected, they can be
distinguished by appending a serial number, e.g.,
.Ar ft232r:12345678 .
Note that the USB to serial chip has to have a serial number for this to work.
.Nm Avrdude
can check for leading and trailing serial number matches as well.
In the above example,
.Ar ft232r:1234
would also result in a match, and so would
.Ar ft232r:...5678 .
If the USB to serial chip is not known to
.Nm ,
it can be specified using the hexadecimal USB vendor ID, hexadecimal
product ID and an optional serial number, following the serial number
matching rules described above, e.g.,
.Ar usb:0x2341:0x0043
or
.Ar usb:2341:0043:12345678 .
To see a list of currently plugged-in serial ports use -P ?s. In order to
see a list of all possible serial adapters known to
.Nm
use -P ?sa. Depending on the used shell, ? may need to be quoted as in "?"
or \\?.
.Pp
On Win32 operating systems, the parallel ports are referred to as lpt1
through lpt3, referring to the addresses 0x378, 0x278, and 0x3BC,
respectively.  If the parallel port can be accessed through a different
address, this address can be specified directly, using the common C
language notation (i.e., hexadecimal values are prefixed by
.Ql 0x
).
.Pp
For the JTAG ICE mkII and JTAGICE3, if
.Nm
has been configured with libusb support,
.Ar port
can alternatively be specified as
.Pa usb Ns Op \&: Ns Ar serialno .
This will cause
.Nm
to search the programmer on USB.
If
.Ar serialno
is also specified, it will be matched against the serial number read
from any JTAG ICE mkII found on USB.
The match is done after stripping any existing colons from the given
serial number, and right-to-left, so only the least significant bytes
from the serial number need to be given.
.Pp
avrdude -v -P usb:xyz -c jtag2 -p ... 2>&1 | grep ^Found
.Pp
lists all JTAG ICEs
attached to USB, see the section
.Em Example Command Line Invocations
in the detailed pdf documentation.
.Pp
As the AVRISP mkII device can only be talked to over USB, the very
same method of specifying the port is required there.
.Pp
For the USB programmer AVR-Doper running in HID mode, the port must
be specified as
.Ar avrdoper.
Libhidapi support is required on Unix and Mac OS but not on Windows. For more
information about AVR-Doper see https://www.obdev.at/products/vusb/avrdoper.html.
.Pp
For the USBtinyISP, which is a simplistic device not implementing serial
numbers, multiple devices can be distinguished by their location in the
USB hierarchy using -P usb:<busdir>:<devicefile>.
.Pp
For USBasp, multiple devices can also be also distinguished using -P
usb:<busdir>:<devicefile> or using the serial number -P usb:<serialno>.
For examples, see the respective
.Em Troubleshooting
entry in the detailed pdf documentation.
.Pp
The -c pickit5 programmer allows overriding the product ID with a
hexadecimal number <pid> using -P usb::<pid> and the vendor and product
IDs with hexadecimal numbers <vid> and <pid> using -P usb:<vid>:<pid>. The
form -P usb:<serialno> requests AVRDUDE select the PICkit5 programmer with
a serial number that ends in <serialno> (and with vid/pid from the
configuration files).
.Pp
For the XBee programmer the target MCU is to be programmed wirelessly over a
ZigBee mesh using the XBeeBoot bootloader.  The ZigBee 64-bit address for the
target MCU's own XBee device must be supplied as a 16-character hexadecimal
value as a
.Ar port
prefix, followed by the
.Ql @
character, and the serial device to connect to a second directly contactable
XBee device associated with the same mesh (with a default baud rate of 9600).
This may look similar to:
.Pa 0013a20000000001@/dev/tty.serial .
.Pp
For diagnostic purposes, if the target MCU with an XBeeBoot bootloader is
connected directly to the serial port, the 64-bit address field can be
omitted.  In this mode the default baud rate will be 19200.
.Pp
For programmers that attach to a serial port using some kind of
higher level protocol (as opposed to bit-bang style programmers),
.Ar port
can be specified as
.Pa net Ns \&: Ns Ar host Ns \&: Ns Ar port .
In this case, instead of trying to open a local device, a TCP
network connection to (TCP)
.Ar port
on
.Ar host
is established.
Square brackets may be placed around
.Ar host
to improve readability, for numeric IPv6 addresses (e.g.
.Li net:[2001:db8::42]:1337 ) .
The remote endpoint is assumed to be a terminal or console server
that connects the network stream to a local serial port where the
actual programmer has been attached to.
The port is assumed to be properly configured, for example using a
transparent 8-bit data connection without parity at 115200 Baud
for a STK500.
.Pp
Note: The ability to handle IPv6 hostnames and addresses is limited to
Posix systems (by now).
.It Fl q \-quell
Disable (or quell) output of the progress bar while reading or writing
to the device.  Specify it more often for even quieter operations.
.It Fl T Ar cmd
Run terminal line
.Ar cmd
when it is its turn in relation to other -t interactive terminals
-T terminal commands and -U memory operations. Except for the simplest
of terminal commands the argument
.Ar cmd
will most likely need to be set in quotes, see your OS shell manual for
details. See below for a detailed description of all terminal commands.
.It Fl t \-terminal
Tells
.Nm
to run an interactive terminal when it is its turn in relation to
other -t interactive terminals, -T terminal commands and -U memory
operations.
.It Xo Fl U \-memory Ar memory Ns
.Ar \&: Ns Ar op Ns
.Ar \&: Ns Ar filename Ns
.Op \&: Ns Ar format
.Xc
Perform a memory operation as indicated  when it is its turn in relation to
other -t interactive terminals, -T terminal commands and -U memory
operations. The
.Ar memory
field specifies the memory to operate on. From version 8.0 the memory
field can also be a comma-separated list of memories, eg,
.Ar flash,eeprom ;
also, Intel Hex or Motorola S-Record files generated by AVRDUDE can store
multiple memories. The special memory
.Ar ALL
expands to all memories that a part has while
.Ar all
expands to all memories with exception of sub-memories.
.Ar etc
is the same as
.Ar all ;
this can be used to change the order in which memories are written to
or read from file, eg,
.Ar signature,etc
is a list of all memories such that the
.Ar signature
memory comes first. It is possible to remove a memory from the list so far
by preceding a minus or backslash, eg,
.Ar all,-calibration .
The available memory types are device-dependent, the actual configuration
can be viewed with the
.Cm part
command in terminal mode.
.Pp
Typically, a device's memory configuration at least contains
the memories
.Ar flash ,
.Ar eeprom ,
.Ar signature
and
.Ar lock ,
which is sometimes known as
.Ar lockbits .
The
.Ar signature
memory contains the three device signature bytes, which should
be, but not always are, unique for the part. The
.Ar lock
memory of one or four bytes typically details whether or not external
reading/writing of the flash memory, or parts of it, is allowed. After
restricting access via the lock memory, often the only way to unlock
memory is via a chip erase. Parts will also typically have fuse bytes,
which are read/write memories for configuration of the device and
calibration memories that typically contain read-only factory calibration
values.
.Pp
The flash memory, being physically implemented as NOR-memory, is special
in the sense that it is normally only possible to program bits to change
from 1 to 0. Before reprogramming takes place normally flash memory has
to be erased. Older parts would only offer a chip erase to do so, which
also erases EEPROM unless a fuse configuration preserves its contents. If
AVRDUDE detects a -U option that writes to a flash memory it will
automatically trigger a chip erase for these older parts.  ATxmegas or
UPDI parts (AVR8X family) offer a page erase, and AVRDUDE takes advantage
of that by erasing pages before programming them unless -e (chip erase) or
-D (do not erase before writing) was requested. It should be noted that in
absence of the -e chip erase option any ATxmega or UPDI flash pages not
affected by the programming will retain their previous content.
.Pp
For a list of all known memories, please refer to the full documentation, eg,
.Li https://github.com/avrdudes/avrdude/blob/main/avrdude.pdf
.Pp
The
.Ar op
field specifies what operation to perform:
.Bl -tag -width noreset
.It Ar r
read device memory and write to the specified file
.It Ar w
read data from the specified file and write to the device memories in the
list; read-only memories in a memory list are skipped, as are fuses and
lock bits when the programmer is a bootloader; writing to single read-only
memories fails only if the contents differs between the file and memory
.It Ar v
read data from both the device and the specified file and perform a verify
.El
.Pp
The
.Ar filename
field indicates the name of the file to read or write.
The
.Ar format
field is optional and contains the format of the file to read or
write.
.Ar Format
can be one of:
.Bl -tag -width sss
.It Ar i
Intel Hex
.It Ar I
Intel Hex with comments on reading from, and tolerance of checksum errors, writing to the AVR
.It Ar s
Motorola S-Record
.It Ar r
raw binary; little-endian byte order, in the case of the flash data
.It Ar e
ELF (Executable and Linkable Format, for input only)
.It Ar m
immediate mode; actual byte values are specified on the command line,
separated by commas or spaces in place of the filename field of the -U
option.  This is useful for programming fuse bytes without having to
create a single-byte file or enter terminal mode.
.It Ar a
auto detect; valid for input only, and only if the input is not
provided at
.Em stdin .
.It Ar d
decimal; this and the following formats generate one line of output for
the respective memory section, forming a comma-separated list of the
values. This can be particularly useful for subsequent processing, like
for fuse bit settings.
.It Ar h
hexadecimal; each value will get the string
.Em 0x
prepended.
.It Ar o
octal; each value will get a
.Em 0
prepended unless it is less than 8 in which case it gets no prefix.
.It Ar b
binary; each value will get the string
.Em 0b
prepended.
.El
.Pp
When used as input, the
.Ar m ,
.Ar d ,
.Ar h ,
.Ar o
and
.Ar b
formats will use the same code for reading lists of numbers separated by
white space and/or commas. The read routine handles decimal, hexadecimal,
octal or binary numbers on a number-by-number basis, and the list of
numbers can therefore be of mixed type. In fact the syntax, is the same as
for data used by the terminal write command, i.e., the file's input data can
also be 2-byte short integers, 4-byte long integers or 8-byte long long
integers, 4-byte floating point numbers, 8-byte double precision numbers,
C-type strings with a terminating nul or C-like characters such as '\t'.
Numbers are written as little endian to memory. When using 0x hexadecimal
or 0b binary input leading zeros are used to determine the size of the
integer, e.g., 0x002a will occupy two bytes and write a 0x2a to memory
followed by 0x00, and 0x01234 will occupy 4 bytes. See the description of
the terminal write command for more details.
.Pp
In absence of an explicit file format, the default is to use auto
detection for input files, raw binary format for output files from a
single memory read and Intel Hex with comments when an output file is
generated from a list of memories. Note that while
.Nm avrdude
will generate a single output file from a memory list for all formats with
the exception of elf (:e) it only recognises Intel hex (:I or :i),
Motorola S-Record (:s) or elf files (:e, generated by the compiler) as
valid multi-memory files when reading a file for verifying or writing
memories. Note also that if a
.Ar filename
contains a colon as penultimate character the
.Ar format
field is no longer optional since the last character
would otherwise be misinterpreted as
.Ar format .
.Pp
When reading any kind of flash memory area (including the various sub-areas
in Xmega devices), the resulting output file will be truncated to not contain
trailing 0xFF bytes which indicate unprogrammed (erased) memory.
Thus, if the entire memory is unprogrammed, this will result in an output
file that has no contents at all.  This behaviour can be overridden with
the -A option.
.Pp
As an abbreviation, the form
.Fl U Ar filename
is equivalent to specifying
.Fl U Em flash:w: Ns Ar filename Ns :a .
This will only work if
.Ar filename
does not have a pair of colons in it that sandwich a single character
as otherwise the first part might be interpreted as memory, and the single
character as memory operation.
.Pp
A file name used for writing to flash that starts with urboot:
autogenerates an urboot bootloader file. Try for example -c dryrun -U
urboot:help for a list of features that determine the contents of the
bootloader. Other than that there is detailed documentation for
autogenerated files in the AVRDUDE pdf manual, eg, at
.Li https://github.com/avrdudes/avrdude/blob/main/avrdude.pdf
Writing urboot:... files to flash using -U has the desired side-effect of
also writing all necessary fuse configurations for the bootloader to work.
.It Fl v \-verbose
Enable verbose output.
More
.Fl v
options increase verbosity level.
.It Fl V \-noverify-memory
Disable automatic verify check when writing data to the AVR with -U.
.It Fl \-version
Print version and exit
.It Fl x Ar extended_param
Pass
.Ar extended_param
to the chosen programmer implementation as an extended parameter.
The interpretation of the extended parameter depends on the
programmer itself.
See below for a list of programmers accepting extended parameters
or issue
.Nm
-x help ... to see the extended options of the chosen programmer.
.El
.Ss Terminal mode
In this mode,
.Nm
only initializes communication with the MCU, and then awaits user
commands on standard input.  Commands and parameters may be
abbreviated to the shortest unambiguous form.  Terminal mode provides
a command history using
.Xr readline 3 ,
so previously entered command lines can be recalled and edited.
.Pp
The
.Ar addr
and
.Ar len
parameters of the dump, read, disasm, write, save and erase commands can
be negative with the same syntax as substring computations in perl or
python. The table below defines the effective memory interval
.Ar [start ,
.Ar end],
given the memory size
.Ar sz :
.Pp
.nf
addr    len  Memory interval     Comment
------------------------------------------------------------------------
0/pos   pos  [addr, addr+len-1]  Note: len = end-start+1
0/pos   neg  [addr, sz+len]      End is |len| bytes below memory size sz
  neg   pos  [sz+addr,           Start is |addr| bytes below memory size
                 sz+addr+len-1]
  neg   neg  [sz+addr, sz+len]   Combining above two cases
  any     0  empty set           No action
.fi
.Pp
Note that addr must be in the range [-sz, sz-1]. After computing the memory interval
[start, end] as per above table, the effective length end-start + 1 must not be negative; if
the effective length is zero then no action is carried out. End may be beyond the available
memory for the dump, read or disasm commands, in which case the operation wraps around
the memory end, but the effective length is always limited to the memory size.
.Pp
Here some examples for a memory with size sz of 0x800 (2048) bytes:
.Pp
.nf
addr    len  Memory interval     Comment
------------------------------------------------------------------------
0x700    12  [0x700, 0x70b]      Conventional use
 1024  -257  [0x400, 0x6ff]      Size of memory is 2048 or 0x800
 -512   512  [0x600, 0x7ff]      Last 512 bytes
 -256    -1  [0x700, 0x7ff]      Last 256 bytes
    0    49  [0, 48]             First 49 bytes
    0   -49  [0, 1999]           All but the last 48 = |len+1| bytes
    0    -1  [0, 0x7ff]          All memory without knowing its size
 2046     4  [0x7fe, 0x801]      Wrap around for read but error for write
 2046  4096  [0x7fe, 0x17fe]     Read wrap around stops at 0x7fd
   -1    -1  [0x7ff, 0x7ff]      One byte at 0x7ff is addressed
   -1    -2  [0x7ff, 0x7fe]      No action: effective length is zero
   -1    -3  [0x7ff, 0x7fd]      Error: effective length is negative
.fi
.Pp
The following commands are implemented for all programmers:
.Bl -tag -offset indent -width indent
.It Ar dump memory addr len
Read from the specified memory interval (see above), and display in the usual
hexadecimal and ASCII form.
.It Ar dump memory addr
Read from
.Ar memory addr
as many bytes as the most recent
.Ar dump memory addr len command
with this very memory had specified (default 256 bytes), and display them.
.It Ar dump memory
Continue dumping the contents from the same memory where the previous
.Ar dump memory
command left off.
.It Ar dump
Continue dumping from the memory and location where the most recent
.Ar dump
command left off; if no previous dump command has addressed a memory an error message will be shown.
.It Ar dump memory addr ...
Read all bytes from the specified memory starting at address
.Ar addr Ns ,
and display them (deprecated: use dump memory addr -1).
.It Ar dump memory ...
Read all bytes from the specified memory, and display them (deprecated: use dump memory 0 -1).
.It Ar read
Can be used as an alias for dump.
.It Ar disasm [opts] [arguments]
Like dump, the disasm command displays a part of the specified memory,
albeit by interpreting the memory contents as AVR opcodes and showing it
as assembler source code. Unlike dump, the disasm command has options;
these control how disasm displays its result (see below). Other than that,
the syntax of specifying the memory and its to be processed interval is
virtually the same as that of dump: the default disasm length is 32 bytes,
though, and sometimes the length can be slightly shorter or longer than
requested, so that the memory section for disasm aligns with opcodes.
Disasm options, once set, stay in force until switched off, typically by
changing the case of the option. This way, a simple disasm without further
options can be used to step through memory keeping the appearance. Disasm
knows the following options:
.Bl -tag -offset indent -width indent
.It -g
Generate avr-gcc source: this sets -sOFQ and outputs a .text preamble and
a main symbol unless the disassembly emits one itself; -G (the default)
switches off -g and stops outputting a preamble
.It -A
Do not show addresses; -a (the default) shows addresses
.It -O
Do not show opcode bytes; -o (the default) show opcode bytes
.It -C
Do not show comments; -c (the default) show comments
.It -f
Show affected flags in SREG, eg, ---SVNZC for the sbiw opcode; -F (the
default) do not show SREG flags
.It -q
Show the number of machine cycles that an opcode takes; -Q (the default)
do not show the cycles
.It -n
Put the opcode full name into comment, eg, subtract immediate from word
for the sbiw opcode; -N (the default) do not show the full opcode names
.It -e
Put a technical explanation of the opcode into the comment, eg, Rd+1:Rd
<-- Rd+1:Rd - K for the sbiw opcode; -E (the default) do not show
technical explanations
.It -S
Use AVR instruction set style: this means that register pairs are shown
as, eg, in r31:30 instead of r30; -s (the default) use avr-gcc code style
.It -L
Do not preprocess labels; -l (the default) preprocess jump/call labels
.It -U
Do not show unused labels; -u (the default) show unused tagged labels
.It -d
Decode all opcodes including those that are undocumented; -D (the default)
decode only opcodes that are valid for the part
.It -z
Zap the list of jumps and calls before disassembly
.It -t=<file>
Delete symbols from a previously read tagfile, if any, and read the tagfile
<file> for assigning addresses to symbol names
.El
The tagfile is an ASCII file where each line describes a symbol for code
label addresses (L), variable addresses in flash (P) and variables
addresses in memory or I/O space (M). Hashmarks start a tagfile comment
that extends to the end of the line and is ignored by disasm. Here is a
defining example of how a tagfile looks like
.nf
---------------------------------------------------------------
0x7f54 L        putch     Outputs a char # L are code labels
0x7ffe P W 1    version16 A word integer # P are PGM data
0x7f80 P A 4    headings  Column headers # Auto-aligned strings
0x0100 M B 2048 sram      2 kB SRAM      # Memory address
---------------------------------------------------------------
.fi
Code labels L can be, eg, function names in program space or goto labels.
They use up to four columns separated by white space: the address, the
letter L, the symbolic name of the label and an optional comment column
for the symbol, which is copied by disasm into the disassembly comment
column, should this label be referenced or used by the code. Variable
symbols have a P or M in the second column; they can be bytes or words (16
bits) as determined by the letter B or W in the third column and either
single variables or arrays as specified by the multiplicity count in the
forth column. P symbols, but not M symbols, can also encode chars (8
bits), longs (32 bits), quads (64 bits) or octas (128 bits) as signified
by the letters C, L, Q or O, respectively, or be the base location of
nul-terminated strings as encoded by A or S in the third column. Out of
necessity, the space occupied by A/S strings varies. The difference
between A and S symbols is that the array of A strings might have an
additional nul character to auto-align the space occupied by them to an
even address. The fifth column is the symbolic name for the P or M address
that can be used by disasm to output relevant addresses symbolically. P
areas described in the tagfile also tell disasm that the corresponding
area is not code and should not be disassembled as such; instead the
directives .byte, .word, .asciz and sometimes at the end of the memory
section .ascii are used for disassembly of that area. As with L labels, P
and M variables may have an optional final comment column pertaining to
the symbol that may be output in the disassembly column as and when the
corresponding variables are used.
.Pp
Tagfiles are useful for disassembly to make the output of disasm more
readable. They can be built manually and incrementally as one's
understanding of the code grows. Alternatively, the bash shell script
elf2tag can automatically generate a tag file from the .elf file that
produced the flash contents:
.Pp
$ elf2tag file.elf >file.tag
.Pp
elf2tag uses the avr-objdump -d disassembly to create L labels and avr-nm
to generate M symbols.
.It Ar write memory addr data[,] {data[,]}
Manually program the respective memory cells, starting at address
.Ar addr ,
using the data items provided.
The terminal implements reading from and writing to flash, EEPROM, bootrow and
usersig type memories normally through a cache and paged access functions.
All other memories are directly written to without use of a cache. Some
older parts without paged access, depending on the programmer, might also
have flash and EEPROM directly accessed without cache.
.Pp
.Ar data
can be binary, octal, decimal or hexadecimal integers, floating point numbers
or C-style strings and characters. If nothing matches,
.Ar data
will be interpreted as the name of a file containing data, which will be
read and inserted at this point. In order to force the interpretation of a
data item as file, e.g., when the file name would be understood as a number
otherwise, the file name can be given a
.Ar :f
format specifier. In absence of a format suffix, the terminal will try
to auto-detect the file format.
.Pp
A file name that starts with urboot: autogenerates an urboot bootloader
file. Try for example the terminal command write flash urboot:help for a
list of features that determine the contents of the bootloader. Other than
that there is detailed documentation for autogenerated files in the AVRDUDE
pdf manual, eg, at
.Li https://github.com/avrdudes/avrdude/blob/main/avrdude.pdf
It is worth noting here that writing urboot:... files to flash in the
terminal does not write the necessary fuses for the bootloader to work (in
contrast to -U operations).
.Pp
For integers, an optional case-insensitive suffix specifies the data size: HH
8 bit, H/S 16 bit, L 32 bit, LL 64 bit. Suffix D indicates a 64-bit double, F
a 32-bit float, whilst a floating point number without suffix defaults to
32-bit float. Hexadecimal floating point notation is supported. An ambiguous
trailing suffix, e.g., 0x1.8D, is read as no-suffix float where D is part of
the mantissa; use a zero exponent 0x1.8p0D to clarify.
.Pp
An optional U suffix makes integers unsigned. Ordinary 0x hexadecimal and 0b
binary integers are always treated as unsigned. +0x, -0x, +0b and -0b numbers
with an explicit sign are treated as signed unless they have a U suffix.
Unsigned integers cannot be larger than 2^64-1. If n is an unsigned integer
then -n is also a valid unsigned integer as in C. Signed integers must fall
into the [-2^63, 2^63-1] range or a correspondingly smaller range when a
suffix specifies a smaller type.
.Pp
Ordinary 0x hexadecimal and 0b binary integers with n digits (counting
leading zeros) use the smallest size of one, two, four and eight bytes that
can accommodate any n-digit hexadecimal/binary integer. If an integer suffix
specifies a size explicitly the corresponding number of least significant
bytes are written, and a warning shown if the number does not fit into the
desired representation. Otherwise, unsigned integers occupy the smallest of
one, two, four or eight bytes needed. Signed numbers are allowed to fit into
the smallest signed or smallest unsigned representation: For example, 255 is
stored as one byte as 255U would fit in one byte, though as a signed number
it would not fit into a one-byte interval [-128, 127]. The number -1 is
stored in one byte whilst -1U needs eight bytes as it is the same as
0xFFFFffffFFFFffffU.
.Pp
One trailing comma at the end of
.Ar data
items is ignored to facilitate copy & paste of lists.
.It Ar write memory data
The start address may be omitted if the size of the memory being written
to is one byte.
.Ar data
can be anything including a file.
.It Ar write memory file
The start address may be omitted when a file is written to the memory.
.It Ar write memory addr len data[,] {data[,]} ...
The ellipsis ... form writes the data to the entire memory intervall addressed by
.Ar addr len
and, if necessary, pads the remaining space by repeating the last
.Ar data
item. The fill write command does not write beyond the specified memory area
even if more data than needed were given.
.It Ar save memory {addr len} file[:format]
Save one or more memory segments to a file in a format specified by the
:format letter. The default is :r for raw binary. Each memory segment is
described by an address and length pair. In absence of any memory segments
the entire memory is saved to the file. Only Motorola S-Record (:s) and
Intel Hex (:i or :I) formats store address information with the saved
data.
.Nm Avrdude
cannot currently save ELF file formats. All the other file formats lose
the address information and concatenate the chosen memory segments into
the output file. If the file name is - then
.Nm
writes to stdout.
.It Ar backup memlist file[:format]
Backup one or more memories to the specified file using the selected
format. The default format for a single-memory backup is :r (raw
binary); for multi-memory backups it is :I (Intel Hex with comments).
Memlist can be a comma separated list of memories just as in the
.Ar -U
command line argument.
.Ar backup
flushes the cache before reading memories.
.It Ar restore memlist file[:format]
Restore one or more memories from the specified file. It is the user's
responsibility to erase memories as needed beforehand: some paged memories
look like NOR-memory when using certain programmers, meaning programming
cannot set bits to 1 (eg, flash under most programmers). These memories
need to be erased beforehand using the erase command (see below). The
format only needs to be specified if it cannot be automatically detected,
eg, when the file is - for standard input. Memlist can be a comma
separated list of memories just as in the
.Ar -U
command line argument.
.Ar restore
flushes the cache before writing memories and resets the cache after
writing memories. Note that restoring read-only memories verifies file
contents with the corresponding microprocessor's memories.
.It Ar verify memlist file[:format]
Compare one or more memories with the specified file.
Memlist can be a comma separated list of memories just as in the
.Ar -U
command line argument.
.Ar verify
flushes the cache before verifying memories.
.It Ar erase
Perform a chip erase and discard all pending writes to flash, EEPROM and bootrow.
Note that EEPROM will be preserved if the EESAVE fuse bit is active, ie, had
a corresponding value at the last reset prior to the operation.
.It Ar erase memory
Erase the entire specified memory.
.It Ar erase memory addr len
Erase a section of the specified memory.
.It Ar flush
Synchronise with the device all pending writes to flash, EEPROM, bootrow and
usersig. With some programmer and part combinations, flash (and sometimes
EEPROM, too) looks like a NOR memory, i.e., a write can only clear bits,
never set them. For NOR memories a page erase or, if not available, a chip
erase needs to be issued before writing arbitrary data. Usersig is
unaffected by a chip erase. When a memory looks like a NOR
memory, either page erase is deployed (e.g., with parts that have PDI/UPDI
interfaces), or if that is not available, both EEPROM and flash caches are
fully read in, a chip erase command is issued and both EEPROM and flash
are written back to the device. Hence, it can take minutes to ensure that
a single previously cleared bit is set and, therefore, this routine should
be called sparingly.
.It Ar abort
Normally, caches are only ever
actually written to the device when using the
.Ar flush
command, at the end of the terminal session after typing
.Ar quit ,
or after EOF on input is encountered. The abort command resets the cache
discarding all previous writes to the flash, EEPROM, bootrow and usersig cache.
.It Ar config {<-f|-a|-v>}
Show all configuration properties of the part; these are usually bitfields
in fuses or lock bits bytes that can take on values, which typically have
a mnemonic name. Each part has their own set of configurable items.  The
option -f groups the configuration properties by the fuses and lock bits
byte they are housed in, and shows the current value of these memories as
well. Config -a outputs an initialisation script with all properties and
all possible respective assignments. The currently assigned mnemonic
values are the ones that are not commented out. The option -v increases
the verbosity of the output of the config command.
.It Ar config {<-f|-v>} <property> {<-f|-v>}
Show the current value of the named configuration property. Wildcards or
initial strings are permitted (but not both), in which case the current
values of all matching properties are displayed.
.It Ar config {<-f|-v>} <property>= {<-f|-v>}
Show all possible values of the named configuration property (notice the
trailing =). The one that is currently set is the only one not commented
out. As before, wildcards or initial strings are permitted.
.It Ar config {<-f|-v|-c>} <property>=<value> {<-f|-v|-c>}
Modify the named configuration property to the given value. The
corresponding fuse or lock bits will be changed immediately but the change
will normally only take effect the next time the part is reset, at which
point the fuses and lock bits are utilised. Value can either be a valid
integer or one of the symbolic mnemonics, if known. Wildcards or initial
strings are permitted for either the property or the assigned mnemonic
value, but an assignment only happens if both the property and the name
can be uniquely resolved. Option -v shows the value of the assigned
configuration property by reading it again from the fuse. In absence of -v
the option -c confirms the new value of the configuration property only if
it has changed.
.Pp
It is quite possible, as is with direct writing to the underlying fuses
and lock bits, to brick a part, i.e., make it unresponsive to further
programming with the chosen programmer: here be dragons.
.It Ar factory reset
Resets the connected part to factory state as far as possible
(bootloaders, for example, cannot write fuses and may not have a means to
erase EEPROM). This command may change the clock frequency F_CPU of the
part after the next MCU reset when the changed fuse values come into
effect. As such, this may require that future avrdude calls use a
different bit clock rate up to F_CPU/4 for the programmer next time. Note
that the command factory can be abbreviated but the required argument
reset needs to be spelled out in full.
.It Ar regfile {<opts>}
regfile with no further argument displays the register file of a part,
i.e., all register names and their contents in
.Ar io
memory, if possible: note that external programming cannot read the
registers of classic parts (ISP or TPI interfaces).
.Pp
Option -a displays the register I/O addresses in addition; -m displays the
register memory addresses used for lds/sts opcodes instead of the I/O
addresses. Option -s also shows the size of the register in bytes whilst
-v shows a slightly expanded register explanation alongside each register.
.It Ar regfile {<opts>} <reg> {<opts>}
regfile together with a register name
.Em reg
shows all those registers that are matched by
.Em reg.
Wildcards or partial strings are permitted but not both. Register names
have the form
.Em module.name
or
.Em module.instance.name.
If the provided
.Em reg
is a full, existing register name, e.g.,
.Ar porta.out
then that is the only register that is displayed even though that might be
a partial name of another register, eg,
.Ar porta.outdir.
If the provided
.EM reg
is the same as
.Em instance.name
or
.Em name
then partial matching is no longer utilised and all module registers with
that exact
.Em instance.name
or
.Em name
are shown. Partial matching can be forced through use of wildcards, e.g.,
porta.out*
.It Ar regfile {<opts>} <reg>=<value> {<opts>}
This sets a single register addressed by
.Em reg
to the given
.Em value.
Only external programming of modern parts (those with UPDI interface) can
read from and write to register io memory, but as that memory is volatile,
the contents will be lost after reset.
.It Ar include [<opts>] <file>
Include contents of the named file as if it was typed. This is useful for
batch scripts, e.g., recurring initialisation code for fuses. The include
option -e prints the lines of the file as comments before processing them;
on a non-zero verbosity level the line numbers are printed, too.
.It Ar sig
Display the device signature bytes.
.It Ar part
Display the current part information, including supported programming modes,
memory and variants tables. Use
.Ar -m
to only print the memory table, and
.Ar -v
to only print the variants table.
.It Ar verbose Op Ar level
Change (when
.Ar level
is provided), or display the verbosity level.
The initial verbosity level is controlled by the number of
.Fl v
options given on the commandline.
.It Ar quell Op Ar level
Change (when
.Ar level
is provided), or display the quell level. 1 is used to suppress progress reports.
2 or higher yields in progressively quieter operations.
The initial quell level is controlled by the number of
.Fl q
options given on the commandline.
.It Ar \&?
.It Ar help
Give a short on-line summary of the available commands.
.It Ar quit
Leave terminal mode and thus
.Nm avrdude .
.It Ar q
Can be used as an alias for quit.
.It Ar !<line>
Run the shell <line> in a subshell, e.g., !ls *.hex. Subshell commands take the
rest of the line as their command. For security reasons, they must
explictly be enabled by putting
.Pa allow_subshells = yes;
into your
.Pa ${HOME}/.config/avrdude/avrdude.rc
or
.Pa ${HOME}/.avrduderc
file.
.It Ar # <comment>
Place comments onto the terminal line (useful for scripts).
.El
.Pp
The terminal commands below may only be implemented on some specific programmers, and may therefore not be available in the help menu.
.Bl -tag -offset indent -width indent
.It Ar pgerase memory addr
Erase one page of the memory specified.
.It Ar send b1 b2 b3 b4
Send raw instruction codes to the AVR device.  If you need access to a
feature of an AVR part that is not directly supported by
.Nm ,
this command allows you to use it, even though
.Nm
does not implement the command. When using direct SPI mode, up to 3 bytes
can be omitted.
.It Ar spi
Enter direct SPI mode.  The
.Em pgmled
pin acts as chip select.
.Em Supported on parallel bitbang programmers, and partially by USBtiny.
.It Ar pgm
Return to programming mode (from direct SPI mode).
.It Ar vtarg voltage
Set the target's supply voltage to
.Ar voltage
Volts.
.Em Supported on the STK500 and STK600 programmer.
.It Ar varef Oo Ar channel Oc Ar voltage
Set the adjustable voltage source to
.Ar voltage
Volts.
This voltage is normally used to drive the target's
.Em Aref
input on the STK500.
On the Atmel STK600, two reference voltages are available, which
can be selected by the optional
.Ar channel
argument (either 0 or 1).
.Em Supported on the STK500 and STK600 programmer.
.It Ar fosc freq Ns Op M Ns \&| Ns k
Set the programming oscillator to
.Ar freq
Hz.
An optional trailing letter
.Ar \&M
multiplies by 1E6, a trailing letter
.Ar \&k
by 1E3.
.Em Supported on the STK500 and STK600 programmer.
.It Ar fosc off
Turn the programming oscillator off.
.Em Supported on the STK500 and STK600 programmer.
.It Ar sck period
Set the SCK clock period to
.Ar period
microseconds. Note that some official Microchip programmers store the
bitclock setting and will continue to use it until a diferent value is
provided. See
.Em -B bitclock
for more information.
.It Ar parms
Display programmer specific parameters.
.El
.Ss Default Parallel port pin connections
(these can be changed, see the
.Fl c
option)
.TS
ll.
\fBPin number\fP	\fBFunction\fP
2-5	Vcc (optional power supply to MCU)
7	/RESET (to MCU)
8	SCK (to MCU)
9	SDO (to MCU)
10	SDI (from MCU)
18-25	GND
.TE
.Ss DebugWIRE limitations
The debugWIRE protocol is Atmel's proprietary one-wire (plus ground)
protocol to allow an in-circuit emulation of the smaller AVR devices,
using the
.Ql /RESET
line.
DebugWIRE mode is initiated by activating the
.Ql DWEN
fuse, and then power-cycling the target.
While this mode is mainly intended for debugging/emulation, it
also offers limited programming capabilities.
Effectively, the only memory areas that can be read or programmed
in this mode are flash ROM and EEPROM.
It is also possible to read out the signature.
All other memory areas cannot be accessed.
There is no
.Em chip erase
functionality in debugWIRE mode; instead, while reprogramming the
flash ROM, each flash ROM page is erased right before updating it.
This is done transparently by the JTAG ICE mkII (or AVR Dragon).
The only way back from debugWIRE mode is to initiate a special
sequence of commands to the JTAG ICE mkII (or AVR Dragon), so the
debugWIRE mode will be temporarily disabled, and the target can
be accessed using normal ISP programming.
This sequence is automatically initiated by using the JTAG ICE mkII
or AVR Dragon in ISP mode, when they detect that ISP mode cannot be
entered.
.Ss FLIP version 1 idiosyncrasies
Bootloaders using the FLIP protocol version 1 experience some very
specific behaviour.
.Pp
These bootloaders have no option to access memory areas other than
Flash and EEPROM.
.Pp
When the bootloader is started, it enters a
.Em security mode
where the only acceptable access is to query the device configuration
parameters (which are used for the signature on AVR devices).
The only way to leave this mode is a
.Em chip erase .
As a chip erase is normally implied by the
.Fl U
option when reprogramming the flash, this peculiarity might not be
very obvious immediately.
.Pp
Sometimes, a bootloader with security mode already disabled seems to
no longer respond with sensible configuration data, but only 0xFF for
all queries.
As these queries are used to obtain the equivalent of a signature,
.Nm
can only continue in that situation by forcing the signature check
to be overridden with the
.Fl F
option.
.Pp
A
.Em chip erase
might leave the EEPROM unerased, at least on some
versions of the bootloader.
.Ss Programmers accepting extended parameters
.Bl -tag -offset indent -width indent
.It Ar dryrun
.It Ar dryboot
These two programmers emulate programming and accept the following parameters:
.Bl -tag -offset indent -width indent
.It Ar init
Initialise memories with human-readable patterns. Flash memory will be
randomly configured with respect to bootloader, data and code length.
Patterns can best be seen with fixed-width font and the :I format
by inspecting the generated hex file or by using, eg, -U flash:r:-:I.
Patterns in flash memory are executable and represent benign AVR code, ie,
no I/O memory access. Choose a fixed seed for reproducible results.
.It Ar init=<n>
Shortcut for -x init -x seed=<n> (see below)
.It Ar random
Initialise memories with random code and values. Flash memory will be
randomly configured with respect to bootloader, data and code length.
Random code in flash will be benign, that is, not accessing I/O memories,
SRAM or flash. Choose a fixed seed for reproducible results.
.It Ar random=<n>
Shortcut for -x random -x seed=<n>
.It Ar seed=<n>
Seed random number generator with <n>; the default is time(NULL).
Setting this option with a fixed n > 0 will make the random choices
reproducible, ie, they will stay the same between different avrdude
runs.
.It Ar help
Show help menu and exit.
.El
.It Ar JTAG ICE mkII
.It Ar JTAGICE3
.It Ar Atmel-ICE
.It Ar Power Debugger
.It Ar PICkit 4
.It Ar MPLAB SNAP
.It Ar AVR Dragon
When using the JTAG ICE mkII, JTAGICE3, Atmel-ICE, PICkit 4, MPLAB SNAP,
Power Debugger or AVR Dragon in JTAG mode, the following extended parameter
is accepted:
.Bl -tag -offset indent -width indent
.It Ar jtagchain=UB,UA,BB,BA
Setup the JTAG scan chain for
.Ar UB
units before,
.Ar UA
units after,
.Ar BB
bits before, and
.Ar BA
bits after the target AVR, respectively.
Each AVR unit within the chain shifts by 4 bits.
Other JTAG units might require a different bit shift count.
.It Ar hvupdi
.Nm Power Debugger and PICkit 4 only
.sp 0.5
High-voltage UPDI programming is used to enable a UPDI pin that has previously
been set to RESET or GPIO mode. Use
.Ar -x hvupdi
to enable high-voltage UPDI initialization for targets that supports this.
.It Ar vtarg=VALUE, vtarg
.Nm Power Debugger only
.sp 0.5
The voltage generator can be enabled by setting a target voltage.
The current set-voltage can be read by
.Ar -x vtarg
alone.
.It Ar help
Show help menu and exit.
.El
.It Ar PICkit 4
.It Ar MPLAB SNAP
.Bl -tag -offset indent -width indent
.It Ar mode=avr
Switch programmer to AVR mode, then exit if not already in AVR mode
.It Ar mode=<mplab|pic>
Switch programmer to MPLAB aka PIC mode, then exit
.Pp
The PICkit 4 and MPLAB SNAP programmer can only be utilised by
.Nm
when in AVR mode. Use
.Ar -x mode=avr
for switching to AVR mode, or
.Ar -x mode=mplab
for switching (back) to MPLAB mode.
.It Ar help
Show help menu and exit.
.El
.It Ar PICkit 5
.It Ar PICkit 4 (PIC mode)
.Bl -tag -offset indent -width indent
.It Ar vtarg=<voltage>
Specify a voltage between 1.8 and 5.5 V that the programmer should supply
to the target. If there is already a valid voltage applied to the VTG Pin,
this setting will be ignored. When AVRDUDE detects an external voltage outside
of this range, it will terminate the operation. You can disable this check by
setting the voltage to 0 V. If an XMEGA part was selected, a requested voltage
above 3.49 V will lead to an abort of operation.
.It Ar hvupdi
High-voltage UPDI programming is used to enable a UPDI pin that has previously
been set to RESET or GPIO mode. Use -x hvupdi to enable high-voltage UPDI
initialization for supported targets. Depending on the target, the HV pulse will
be applied either on the RST pin, or the UPDI pin.
.It Ar help
Show help menu and exit.
.El
.It Ar Xplained Mini (ISP and UPDI)
.Bl -tag -offset indent -width indent
.It Ar suffer=VALUE, suffer
The SUFFER register allows the user to modify the behavior of the on-board mEDBG.
The current state can be read by
.Ar -x suffer
alone.
.Bl -tag -offset indent -width indent
.It Bit 7 ARDUINO:
Adds control of extra LEDs when set to 0
.It Bit 6..3:
Reserved (must be set to 1)
.It Bit 2 EOF:
Agressive power-down, sleep after 5 seconds if no USB enumeration when set to 0
.It Bit 1 LOWP:
forc running the mEDBG at 1 MHz when bit set to 0
.It Bit 0 FUSE:
Fuses are safe-masked when bit sent to 1. Fuses are unprotected when set to 0
.El
.El
.Pp
.Bl -tag -offset indent -width indent
.It Ar vtarg_switch=VALUE, vtarg_switch
The on-board target voltage switch can be turned on or off by writing a 1 or
a 0. The current state can be read by
.Ar -x vtarg_switch
alone.
Note that the target power switch will always be on after a power cycle.
Also note that the smaller Xplained Nano boards does not have a target power switch.
.It Ar help
Show help menu and exit.
.El
.It Ar Curiosity Nano
.Bl -tag -offset indent -width indent
.It Ar vtarg=VALUE, vtarg
The generated on-board target voltage can be changed by specifying a new voltage.
The current set-voltage can be read by
.Ar -x vtarg
alone.
.It Ar help
Show help menu and exit.
.El
.It Ar STK500
.It Ar STK600
.Bl -tag -offset indent -width indent
.It Ar vtarg=VALUE, vtarg
The generated on-board target voltage can be changed by specifying a new voltage.
The current set-voltage can be read by
.Ar -x vtarg
alone.
.It Ar fosc=VALUE[MHz|M|kHz|k|Hz|H], fosc
Set the programmable oscillator frequency. The current frequency can be read by
.Ar -x fosc
alone.
.It Ar varef=VALUE, varef
The generated on-board analog reference voltage can be changed by specifying
a new reference voltage. The current reference voltage can be read by
.Ar -x varef
alone.
.It Ar varef[0,1]=VALUE, varef[0,1]
.Nm STK600 only
.sp 0.5
The generated on-board analog reference voltage for channel 0 or channel 1 can
be changed by specifying a new reference voltage.
The current reference voltage can be read by
.Ar -x varef0
or
.Ar -x varef1
alone.
.It Ar attemps[=<1..99>]
.Nm STK500V1 only
.sp 0.5
Specify how many connection retry attemps to perform before exiting.
Defaults to 10 if not specified.
.It Ar xtal=VALUE[MHz|M|kHz|k|Hz|H]
Defines the XTAL frequency of the programmer if it differs from 7.3728 MHz of the
original STK500. Used by avrdude for the correct calculation of fosc and sck.
.It Ar help
Show help menu and exit.
.El
.It Ar AVR109
.Bl -tag -offset indent -width indent
.It Ar autoreset
Toggle RTS/DTR lines on port open to issue a hardware reset.
.It Ar help
Show help menu and exit.
.El
.It Ar AVR910
.Bl -tag -offset indent -width indent
.It Ar devcode=VALUE
Override the device code selection by using
.Ar VALUE
as the device code.
The programmer is not queried for the list of supported
device codes, and the specified
.Ar VALUE
is not verified but used directly within the
.Ql T
command sent to the programmer.
.Ar VALUE
can be specified using the conventional number notation of the
C programming language.
.El
.Bl -tag -offset indent -width indent
.It Ar no_blockmode
Disables the default checking for block transfer capability.
Use
.Ar no_blockmode
only if your
.Ar AVR910
programmer creates errors during initial sequence.
.It Ar help
Show help menu and exit.
.El
.It Ar Arduino
.Bl -tag -offset indent -width indent
.It Ar attemps[=<1..99>]
Specify how many connection retry attemps to perform before exiting.
Defaults to 10 if not specified.
.It Ar noautoreset
Don't toggle RTS/DTR lines on port open to prevent a hardware reset.
.It Ar help
Show help menu and exit.
.El
.It Ar Urclock
.Bl -tag -offset indent -width indent
.It Ar showall
Show all info for the connected part, then exit. The -x show... options
below can be used to assemble a bespoke response consisting of a subset
(or only one item) of all available relevant information about the
connected part and bootloader.
.It Ar showid
Show a unique Urclock ID stored in either flash or EEPROM of the MCU, then exit.
.It Ar id=<E|F>.<addr>.<len>
Historically, the Urclock ID was a six-byte unique little-endian number
stored in Urclock boards at EEPROM address 257. The location of this
number can be set by the -x id=<E|F>.<addr>.<len> extended parameter. E
stands for EEPROM and F stands for flash. A negative address addr counts
from the end of EEPROM and flash, respectively. The length len of the
Urclock ID can be between 1 and 8 bytes.
.It Ar showdate
Show the last-modified date of the input file for the flash application,
then exit. If the input file was stdin, the date will be that of the
programming.  Date and filename are part of the metadata that the urclock
programmer stores by default in high flash just under the bootloader; see also
-x nometadata.
.It Ar showfilename
Show the input filename (or title) of the last flash writing session, then exit.
.It Ar title=<string>
When set, <string> will be used in lieu of the input filename. The maximum
string length for the title/filename field is 254 bytes including
terminating nul.
.It Ar showapp
Show the size of the programmed application, then exit.
.It Ar showstore
Show the size of the unused flash between the application and metadata, then exit.
.It Ar showmeta
Show the size of the metadata just below the bootloader, then exit.
.It Ar showboot
Show the size of the bootloader, then exit.
.It Ar showversion
Show bootloader version and capabilities, then exit.
.It Ar showvector
Show the vector number and name of the interrupt table vector used by the
bootloader for starting the application, then exit. For hardware-supported
bootloaders this will be vector 0 (Reset), and for vector bootloaders this
will be any other vector number of the interrupt vector table or the slot
just behind the vector table with the name VBL_ADDITIONAL_VECTOR.
.It Ar showpart
Show the part for which the bootloader was compiled, then exit.
.It Ar bootsize=<size>
Manual override for bootloader size. Urboot bootloaders put the number of
used bootloader pages into a table at the top of the bootloader section,
i.e., typically top of flash, so the urclock programmer can look up the
bootloader size itself. In backward-compatibility mode, when programming
via other bootloaders, this option can be used to tell the programmer the
size, and therefore the location, of the bootloader.
.It Ar vectornum=<n>
Manual override for vector number. Urboot bootloaders put the vector
number used by a vector bootloader into a table at the top of flash, so
this option is normally not needed for urboot bootloaders. However, it is
useful in backward-compatibility mode (or when the urboot bootloader does
not offer flash read). Specifying a vector number in these circumstances
implies a vector bootloader whilst the default assumption would be a
hardware-supported bootloader.
.It Ar eepromrw
Manual override for asserting EEPROM read/write capability. Not normally
needed for urboot bootloaders, but useful for in backward-compatibility
mode if the bootloader offers EEPROM read/write.
.It Ar emulate_ce
If an urboot bootloader does not offer a chip erase command it will tell
the urclock programmer so during handshake. In this case the urclock
programmer emulates a chip erase, if warranted by user command line
options, by filling the remainder of unused flash below the bootloader
with 0xff. If this option is specified, the urclock programmer will assume
that the bootloader cannot erase the chip itself. The option is useful
for backwards-compatible bootloaders that do not implement chip erase.
.It Ar restore
Write unchanged flash input files and trim below the bootloader if
needed. This is most useful when one has a backup of the full flash and
wants to play that back onto the device. No metadata are written in this
case and no vector patching happens either if it is a vector bootloader.
However, for vector bootloaders, even under the option -x restore an
input file will not be written to the AVR for which the reset vector does not point
to the vector bootloader. This is to avoid writing an input file to the
device that would render the vector bootloader not functional as it would
not be reached after reset.
.It Ar initstore
On writing to flash fill the store space between the flash application and
the metadata section with 0xff.
.It Ar nofilename
On writing to flash do not store the application input filename (nor a title).
.It Ar nodate
On writing to flash do not store the application input filename (nor a
title) and no date either.
.It Ar nostore
On writing to flash do not store metadata except the metadata code byte
0xff saying there are no metadata.  In particular, no data store frame is
programmed.
.It Ar noautoreset
Don't toggle RTS/DTR lines on port open to prevent a hardware reset.
.It Ar nometadata
Do not support any metadata. The full flash besides the bootloader is
available for the application. If the application is smaller than the
available space then a metadata code byte 0xff is stored nevertheless to
indicate there are no further metadata available. In absence of
-x nometadata, the default for the urclock programmer is to write as much
metadata (filename, data and store information) as the size of the
application and the other extended options allow. The subtle
difference between -x nometadata and -x nostore is that the latter always
explicitly stores in flash that no further metadata are available, so that
a such prepared flash can always be queried with
.Nm
-x showall. In contrast to this, it cannot be guaranteed that a -x showall
query on flash prepared with -x nometadata yields useful results.
.It Ar delay=<n>
Add a <n> ms delay after reset. This can be useful if a board takes a
particularly long time to exit from external reset. <n> can be negative,
in which case the default 120 ms delay after issuing reset will be
shortened accordingly.
.It Ar strict
Urclock has a faster, but slightly different strategy than -c arduino to
synchronise with the bootloader; some stk500v1 bootloaders cannot cope
with this, and they need the -x strict option.
.It Ar help
Show help menu and exit.
.El
.It Ar buspirate
.Bl -tag -offset indent -width indent
.It Ar reset=cs,aux,aux2
The default setup assumes the BusPirate's CS output pin connected to
the RESET pin on AVR side. It is however possible to have multiple AVRs
connected to the same BP with SDI, SDO and SCK lines common for all of them.
In such a case one AVR should have its RESET connected to BusPirate's
.Pa CS
pin, second AVR's RESET connected to BusPirate's
.Pa AUX
pin and if your BusPirate has an
.Pa AUX2
pin (only available on BusPirate version v1a with firmware 3.0 or newer)
use that to activate RESET on the third AVR.
.Pp
It may be a good idea to decouple the BusPirate and the AVR's SPI buses from
each other using a 3-state bus buffer. For example 74HC125 or 74HC244 are some
good candidates with the latches driven by the appropriate reset pin (cs,
aux or aux2). Otherwise the SPI traffic in one active circuit may interfere
with programming the AVR in the other design.
.It Ar spifreq=<0..7>
The SPI speed for the Bus Pirate's binary SPI mode:
.Bd -literal
0 ..  30 kHz   (default)
1 .. 125 kHz
2 .. 250 kHz
3 ..   1 MHz
4 ..   2 MHz
5 ..   2.6 MHz
6 ..   4 MHz
7 ..   8 MHz
.Ed
.It Ar rawfreq=<0..3>
Sets the SPI speed and uses the Bus Pirate's binary "raw-wire" mode:
.Bd -literal
0 ..   5 kHz
1 ..  50 kHz
2 .. 100 kHz   (Firmware v4.2+ only)
3 .. 400 kHz   (v4.2+)
.Ed
.Pp
The only advantage of the "raw-wire" mode is the different SPI frequencies
available. Paged writing is not implemented in this mode.
.It Ar ascii
Attempt to use ASCII mode even when the firmware supports BinMode (binary
mode).
BinMode is supported in firmware 2.7 and newer, older FW's either don't
have BinMode or their BinMode is buggy. ASCII mode is slower and makes
the above
.Ar reset= , spifreq=
and
.Ar rawfreq=
parameters unavailable. Be aware that ASCII mode is not guaranteed to work
with newer firmware versions, and is retained only to maintain compatibility
with older firmware versions.
.It Ar nopagedwrite
Firmware versions 5.10 and newer support a binary mode SPI command that enables
whole pages to be written to AVR flash memory at once, resulting in a
significant write speed increase. If use of this mode is not desirable for some
reason, this option disables it.
.It Ar nopagedread
Newer firmware versions support in binary mode SPI command some AVR Extended
Commands. Using the "Bulk Memory Read from Flash" results in a
significant read speed increase. If use of this mode is not desirable for some
reason, this option disables it.
.It Ar cpufreq=<125..4000>
This sets the AUX pin to output a frequency of
.Ar n
kHz. Connecting
the AUX pin to the XTAL1 pin of your MCU, you can provide it a clock,
for example when it needs an external clock because of wrong fuses settings.
Make sure the CPU frequency is at least four times the SPI frequency.
.It Ar serial_recv_timeout=<1...>
This sets the serial receive timeout to the given value.
The timeout happens every time avrdude waits for the BusPirate prompt.
Especially in ascii mode this happens very often, so setting a smaller value
can speed up programming a lot.
The default value is 100ms. Using 10ms might work in most cases.
.It Ar help
Show help menu and exit.
.El
.It Ar Micronucleus bootloader
.Bl -tag -offset indent -width indent
.It Ar wait[=<timeout>]
If the device is not connected, wait for the device to be plugged in.
The optional
.Ar timeout
specifies the connection time-out in seconds.
If no time-out is specified, AVRDUDE will wait indefinitely until the
device is plugged in.
.It Ar help
Show help menu and exit.
.El
.It Ar Teensy bootloader
.Bl -tag -offset indent -width indent
.It Ar wait[=<timeout>]
If the device is not connected, wait for the device to be plugged in.
The optional
.Ar timeout
specifies the connection time-out in seconds.
If no time-out is specified, AVRDUDE will wait indefinitely until the
device is plugged in.
.It Ar help
Show help menu and exit.
.El
.It Ar Wiring
When using the Wiring programmer type, the
following optional extended parameters are accepted:
.Bl -tag -offset indent -width indent
.It Ar snooze=<n>
After performing the port open phase, AVRDUDE will wait/snooze for
.Ar snooze
milliseconds before continuing to the protocol sync phase.
No toggling of DTR/RTS is performed if
.Ar snooze
is greater than 0.
.It Ar delay=<n>
Add a <n> milliseconds delay after resetting the part through toggling the
DTR/RTS lines. This can be useful if a board takes a particularly long
time to exit from external reset. <n> can be negative, in which case the
default 100 ms delay after issuing reset will be shortened accordingly.
.It Ar noautoreset
Don't toggle RTS/DTR lines on port open to prevent a hardware reset.
.It Ar help
Show help menu and exit.
.El
.It Ar PICkit2
Connection to the PICkit2 programmer:
.Bd -literal
(AVR)    (PICkit2)
RST  -   VPP/MCLR (1)
VDD  -   VDD Target (2) -- possibly optional if AVR self powered
GND  -   GND (3)
SDI  -   PGD (4)
SCLK -   PDC (5)
SDO  -   AUX (6)
.Ed
.Bl -tag -offset indent -width indent
.It Ar clockrate=<rate>
Sets the SPI clocking rate in Hz (default is 100kHz). Alternately the -B or -i options can be used to set the period.
.It Ar timeout=<usb-transaction-timeout>
Sets the timeout for USB reads and writes in milliseconds (default is 1500 ms).
.It Ar help
Show help menu and exit.
.El
.It Ar USBasp
.Bl -tag -offset indent -width indent
.It Ar section_config
Programmer will erase configuration section with option
.Fl e
(chip erase), rather than entire chip.
Only applicable to TPI devices (ATtiny 4/5/9/10/20/40).
.It Ar help
Show help menu and exit.
.El
.It Ar xbee
.Bl -tag -offset indent -width indent
.It Ar xbeeresetpin=<1..7>
Select the XBee pin DIO<1..7> that is connected to the MCU's
.Ql /RESET
line.  The programmer needs to know which DIO pin to use to reset into the
bootloader.  The default (3) is the DIO3 pin (XBee pin 17), but some
commercial products use a different XBee pin.
.Pp
The remaining two necessary XBee-to-MCU connections are not selectable - the
XBee DOUT pin (pin 2) must be connected to the MCU's
.Ql RXD
line, and the XBee DIN pin (pin 3) must be connected to the MCU's
.Ql TXD
line.
.It Ar help
Show help menu and exit.
.El
.It Ar jtag2updi
.It Ar serialupdi
.Bl -tag -offset indent -width indent
.It Ar rtsdtr=low,high
Forces RTS/DTR lines to assume low or high state during the whole
programming session. Some programmers might use this signal to
indicate UPDI programming state, but this is strictly hardware
specific.
.Pp
When not provided, driver/OS default value will be used.
.It Ar help
Show help menu and exit.
.El
.It Ar linuxspi
.Bl -tag -offset indent -width indent
.It Ar disable_no_cs
Ensures the programmer does not use the SPI_NO_CS bit for the SPI
driver. This parameter is useful for kernels that do not support
the CS line being managed outside the application.
.It Ar help
Show help menu and exit.
.El
.It Ar serprog
.Bl -tag -offset indent -width indent
.It Ar cs
Sets the chip select (CS) to use on supported programmers.
Programmers supporting the 0x16 serprog command can have more than the default CS (0).
This option allows to choose these additional CSes (1, 2, ...) for programming the AVR.
.It Ar help
Show help menu and exit.
.El
.El
.Ss Programmers accepting exitspec parameter
Currently, only the flip2, linuxspi, linuxgpio, raspberry_pi_gpio,
pickit4_mplab, pickit5 and old-school parallel port programmers such as
stk200 and dapa support exitspec parameter.
These let the user decide in which state the programmer pins after ended programming session.
Multiple exitspec options can be separated with commas.
.Bl -tag -offset indent -width indent
.It Ar flip2
.It Ar linuxspi
.It Ar linuxgpio
.It Ar raspberry_pi_gpio
.It Parallel port programmers
.Bl -tag -offset indent -width indent
.It Ar help
Show help menu and exit.
.It Ar reset
The
.Ql /RESET
signal will be left activated at program exit, that is it will be held
.Em low ,
in order to keep the MCU in reset state afterwards.  Note in particular
that the programming algorithm for the AT90S1200 device mandates that
the
.Ql /RESET
signal is active
.Em before
powering up the MCU, so in case an external power supply is used for this
MCU type, a previous invocation of
.Nm
with this option specified is one of the possible ways to guarantee this
condition.
.It Ar noreset
The
.Ql /RESET
line will be deactivated at program exit, thus allowing the MCU target
program to run while the programming hardware remains connected.
.El
.It Parallel port programmers
.Bl -tag -offset indent -width indent
.It Ar vcc
This option will leave those parallel port pins active
.Pq \&i. \&e. Em high
that can be used to supply
.Ql Vcc
power to the MCU.
.It Ar novcc
This option will pull the
.Ql Vcc
pins of the parallel port down at program exit.
.It Ar d_high
This option will leave the 8 data pins on the parallel port active.
.Pq \&i. \&e. Em high
.It Ar d_low
This option will leave the 8 data pins on the parallel port inactive.
.Pq \&i. \&e. Em low
.El
.It Ar Pickit 4 (MPLAB)
.It Ar Pickit 5
.Bl -tag -offset indent -width indent
.It Ar vcc
This option will leave the power supply from the programmer enabled after
avrdude finished the operation. Disabled by default.
.El
.El
.Sh FILES
.Bl -tag -offset indent -width /dev/ppi0XXX
.It Pa /dev/ppi0
Default device to be used for communication with the programming
hardware
.It Pa avrdude.conf
Programmer and parts configuration file
.Pp
On Windows systems, this file is looked up in the same directory as the
executable file.
On all other systems, the file is first looked up in
.Pa ../etc/ ,
relative to the path of the executable, then in the same directory as
the executable itself, and finally in the system default location
.Pa ${PREFIX}/etc/avrdude.conf .
.It Pa ${XDG_CONFIG_HOME}/avrdude/avrdude.rc
Local programmer and parts configuration file (per-user overrides); it follows the same syntax as
.Pa avrdude.conf ;
if the
.Pa ${XDG_CONFIG_HOME}
environment variable is not set or empty, the directory
.Pa ${HOME}/.config/
is used instead.
.It Pa ${HOME}/.avrduderc
Alternative location of the per-user configuration file if above file does not exist
.It Pa ~/.inputrc
Initialization file for the
.Xr readline 3
library
.It Pa <prefix>/share/doc/avrdude/avrdude.pdf
User manual
.El
.\" .Sh EXAMPLES
.Sh DIAGNOSTICS
.Bd -literal
avrdude: jtagmkII_setparm(): bad response to set parameter command: RSP_FAILED
avrdude: jtagmkII_getsync(): ISP activation failed, trying debugWIRE
avrdude: Target prepared for ISP, signed off.
avrdude: Please restart avrdude without power-cycling the target.
.Ed
.Pp
If the target AVR has been set up for debugWIRE mode (i.e., the
.Em DWEN
fuse is programmed), normal ISP connection attempts will fail as
the
.Em /RESET
pin is not available.
When using the JTAG ICE mkII in ISP mode, the message shown indicates
that
.Nm
has guessed this condition, and tried to initiate a debugWIRE reset
to the target.
When successful, this will leave the target AVR in a state where it
can respond to normal ISP communication again (until the next power
cycle).
Typically, the same command is going to be retried again immediately
afterwards, and will then succeed connecting to the target using
normal ISP communication.
.Sh SEE ALSO
.Xr avr-objcopy 1 ,
.Xr ppi 4 ,
.Xr libelf 3 ,
.Xr readline 3
.Pp
The AVR microcontroller product description can be found at
.Pp
.nf
https://www.microchip.com/en-us/products/microcontrollers-and-microprocessors/8-bit-mcus/avr-mcus
.fi
.\" .Sh HISTORY
.Sh AUTHORS
.Nm Avrdude
was initially written by Brian S. Dean <bsd@bdmicro.com>.
.Pp
This man page is by
.ie t J\(:org Wunsch
.el Joerg Wunsch
with updates from Hans Eirik Bull and Stefan R\(:uger
.el Stefan Rueger
amongst others.
.Sh BUGS
Please report bugs via
.Dl "https://github.com/avrdudes/avrdude/issues"
.Pp
The JTAG ICE programmers currently cannot write to the flash ROM
one byte at a time.
For that reason, updating the flash ROM from terminal mode does not
work.
.Pp
Page-mode programming the EEPROM through JTAG (i.e., through an
.Fl U
option) requires a prior chip erase.
This is an inherent feature of the way JTAG EEPROM programming works.
This also applies to the STK500 and STK600 in parallel programming mode.
.Pp
The USBasp and USBtinyISP drivers do not offer any option to distinguish multiple
devices connected simultaneously, so effectively only a single device
is supported.
.Pp
Chip Select must be externally held low for direct SPI when
using USBtinyISP, and send must be a multiple of four bytes.
.Pp
The avrftdi driver allows one to select specific devices using any combination of vid,pid
serial number (usbsn) vendor description (usbvendoror part description (usbproduct)
as seen with lsusb or whatever tool used to view USB device information. Multiple
devices can be on the bus at the same time. For the H parts, which have multiple MPSSE
interfaces, the interface can also be selected.  It defaults to interface 'A'.
